Furnace for low-grade combustibles.



E. KIDWELL.

FURNACE FOR LOW GRADE COMBUSTIBLES.

APPLIQATION FILED OCT. 23. 1912.

1,1 84,35 1 Patented May 23, 1916.

THE COLUMBIA PLANOORAPH 90., WASHXNQTOPLJ. C.

U TED STAT PAEN rric.

EDGAR KIDWECLL, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIG-NOR T0 WASTE UTILITIES COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

FURNACE FOR LOW-GRADE COMBUSTIBLES.

Specification of Letters Patent.

Patented May 23, 1916.

To all whom it may concern I 'Be it known that I, EDGAR KIDWELL a resident of Washington, in theDistrict of Columbia, have invented a new and useful Furnace for Low-Grade Combustibles, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which Figure l is a central vertical section showing one form of furnace constructed in accordance with my invention; Fig. 2 is a similar view showing a modification, and Fig. 3 is a detail view showing a modified form of baffle.

My invention relates to the class of furnaces for burning garbage or low-grade fuels, and particularly to that type wherein the material is brought to a slag condition on an upper grate and then dropped on a lower grate, where it is used for heating air passing to the upper grate. In such furnaces there is a great danger of warping and destroying the upper grate, owing to its direct exposure to the radiant heat from the fuel on the lower grate.

My invention is designed to overcome this difficulty, and it consists in providing a protecting baflie or partition between the upper and lower grates while at the same time allowing the fuel to be dropped from the upper to the lower grate. This dropping down of the charge may be accomplished either by having a movable bafiie or barrier between the two grates, or by having a barrier with a passage around it through which the charge may feed down.

In the drawings, referring to Fig. 1,2 represents the shell and lining of a cupolashaped garbage destructor, into which the charges of garbage are fed through the top opening 3. These charges fall upon a grate 4, which is of any desired or usual form. In

' addition to the air supplied from the lower charges dropped thereon, these charges may be dropped through the hopper-shaped bottom 9 into the car 10. I have shown the grate 8 as also actuated by suitable connections with the hydraulic cylinder 11.

Air is fed in through pipe 12, having a control valve indicated at 13, this air entering below the lower grate 8. The air passing up through the slagged material on the lower grate becomes heated, and is then fed to the fuel on the upper grate in any desirable way. In this figure it passes through a by-pass flue 1 1; though it may pass directly through inclined holes or perforations in the refractory bafiie 5 as shown in Fig. 3. In this case the inclination would serve to prevent radiant heat acting upon the upper grate.

In the use of the apparatus, the charges are dumped upon the upper grate, and burned and slagged thereon, the air being supplied to this grate from one source, and hot air also passing up to it from the lower grate. When the charge is slagged, the hydraulic cylinder is actuated to pull out both the upper grate and the baffle, whereupon the charge falls upon the lower grate. The upper grate and bafiie are then restored to position, another charge is fed on the upper grate, and the operation goes on as before, the charges being dropped from the lower grate at suitable intervals.

In Fig. 2 I show a form similar to that of Fig. 1, except that the bafiie 5 is stationary and takes the form of a horizontally extending hollow ridge of suitable refractory material. In this case the material drops down from the upper grate upon the inclined ledge 15, and slides down through the opening 16 and thence back onto the lower grate. The hot air from the lower grate may also pass up through this opening 16.

The advantages of my invention result from the protection afiorded to the upper of the two grates of a furnace for burning low-grade fuels where there is a slagging action and where the slagged material is held on a lower grate for the purpose of heating air passing through the fresh fuel on the upper grate.

The invention makes the furnace longlived, greatly decreases repairs, and is believed to be essential in furnaces of this type.

Many variations may be made in the form and arrangement of the furnace, the grates, the air supply, &c., without departing from my invention.

I claim r 1. I11 a furnace of low grade combustibles, the combination of superimposed grates, a refractory bafile arranged to cut off the radiant heat from the lower grate to the upper grate, and means for directing the gases from the lower grate to the space below the upper grate; substantially as described.

2. In a furnace for low grade combustibles, the combination of superimposed grates, a refractory baffle arranged to cut off the radiant heat from the lower grate to the upper grate, means for directing the gases from the lower grate to a space below the upper grate, and means for dumping the material from the upper grate onto the lower grate; substantially as described.

3. In a furnace for low grade combustibles, the combination of superimposed cdpilof this patent may be obtained for grates, a refractory baflle arranged to cut off the radiant heat from the lower grate to the upper grate, a passage arranged to conduct the gases arising from the lower grate to the space below the upper grate, and mechanism for moving the upper grate to dump the material therefrom upon the lower grate; substantially as described.

at. A furnace for low grade combustibles having a movable main grate, a lower grate, a movable refractory battle between said grates, and mechanism for moving the battle and main grate in timed relation to each other to allow the material to be dumped directly from the main grate onto the lower grate, substantially as described.

In testimony whereof, I have-hereunto set my hand. V

EDGAR KIDVVELL.

Witnesses:

B. G. Fos'rER, E. G. MCCARTHY.

five cents each, by addressing the Commissioner of .tatelxt: Washington, D. G. 

